172 MR. A. R. WALLACE ON THE ZOOLOGICAL 



grey ; veins black ; pobracliial vein forming an obtuse angle at its 

 junction with the discal transverse vein, the latter very oblique, parted 

 by little more than half its length from the border, and by nearly thrice 

 its length from the praebrachial transverse ; halteres whitish. Length 

 of the body 2i lines ; of the wings 4^ hues. 



Fam. PHOillDiE, Haliday. 

 G-en. Phoba, Latr. 



238. Phora bifasciata, n. s. Fcem. Atra, subtus flavescenti-alba, 

 antennis fulvis, abdomine lanceolato, fasciis duabus apice pedibus 

 halteribusque flavesceuti-albis, pedibus postieis nigris basi flavescenti- 

 albis, tarsis intermediis nigricautibus, alis cinereis. 



Female. Deep black, yellowish white beneath ; antennae tawny ; abdo- 

 men lanceolate, much longer than the thorax; sides elevated, a broad 

 basal yellowish white band, and a narrower one beyond the middle, 

 tip also yellowish white ; anterior legs and halteres yellowish white, 

 middle tarsi blackish, hind femora with the basal half yellowish white ; 

 wings cinereous, veins black, pale at the base ; costal vein ending at 

 a little beyond half the length of the wing ; radial cubital, praebrachial, 

 and pobrachial veins parallel and equally distinct. Length of the 

 body 2-2i lines ; of the wings 5-6 lines. 



On the Zoological Geography of the Malay Archipelago. By 

 Aleeed E. Wallace, Esq. Communicated by Charles 

 Darwin, Esq., F.E.S. & L.S. 



[Read Nov. 3rd, 1859.] 



In Mr. Sclater's paper on the Geographical Distribution of Bii^ds, 

 read before the Linnean Society, and published in the ' Proceed- 

 ings ' for February 1858, he has pointed out that the western 

 islands of the Archipelago belong to the Indian, and the eastern 

 to the Australian region of Ornithology. My researclies in these 

 countries lead me to believe that the same division will hold good 

 in every branch of Zoology ; and the object of my present com- 

 munication is to mark out the precise limits of each region, and 

 to call attention to some inferences of great general importance as 

 regards the study of the laws of organic distribution. 



The Australian and Indian regions of Zoology are very strongly 

 contrasted. In one the Marsupial order constitutes the great mass 

 of the mammalia, — in the other not a solitary marsupial animal 

 exists. Marsupials of at least two genera {discus and Belideus) 

 are found all over the Moluccas and in Celebes ; but none have 



